The invention relates generally to an arrangement for paving a self-setting synthetic elastic surface material, and more particularly, to such a paving arrangement which is preferred for use in forming an athletic ground of a relatively small area such as a tennis court, or a roof-top ground of a building, or an indoor floor for rehabilitation purposes which is coated with such surface material.
It is known to form an athletic ground having a wear resistant and elastic surface by utilizing a molding material which comprises an elastic particulate aggregate such as particles of vulcanized rubber or polymerized plastics and an organic binder. Examples of such organic binder, elastic particulate aggregate or molding material are disclosed in the following prior arts:
1. U.S. Pat. No. 3,272,098 PA1 2. West German Patent Application Laid-Open No. 17 20 263 PA1 3. U.S. Pat. No. 3,801,421 PA1 4. West German Patent Application Laid-Open No. 24 47 625 PA1 5. West German Patent Application Laid-Open No. 24 48 852
An organic binder and elastic particulate aggregate are admixed together with other suitable supplemental additives to produce an unset molding material, which may be poured and laid evenly over a hard base such as asphalt or concrete, whereupon a self-setting occurs and the material is firmly bonded to the base. The setting occurs relatively rapidly, and generally after two or several days, the paved surface is capable of withstanding passage thereon. The unset molding material is a particulate mixture comprising elastic particulate aggregate on which an organic binder having an increased adherence is deposited. Such mixture is difficult to handle during the paving operation as compared with asphalt or concrete. The thickness of a surface coating layer is usually equal to or less than 50 mm, and more generally in a range from 4 to 30 mm. A conventional process of surface pavement comprises pouring unset molding material into a frame of a predetermined area, spreading it to a substantially uniform height, and smoothly compacting it with a hand tool such as a smoothing iron. Skill is required to prevent the unset molding material from adhering to the hand tool. The efficiency of operation is obviously low and the finishing accuracy is less than desirable.
An arrangement which is designed for machine paving of a self-setting synthetic surface material is proposed in aforementioned U.S. Pat. No. 3,272,098. This arrangement is in the form of a truck having wheels which run along a pair of parallel guide pieces laid over the base of a surface to be paved. One end of a screed frame which is open in triangular form is secured to the rear of the truck, and the screed frame rides the guide pieces to be guided thereby as the arrangement runs. The truck carries a binder storage tank and a hopper which receives an elastic aggregate. A mixer is also provided on the truck for admixing the binder and the elastic aggregate which are separately supplied from the tank and the hopper. An unset molding material formed by the mixing operation is dispersed through a chute within an extent defined by the screed frame, which in turn controls the height of the pavement. In a paving operation which utilizes such an arrangement, the unset molding material is spread only by the running screed, and hence there occurs no compression in practice which regulates the density of the material. Accordingly, such an arrangement is not suitable for pavement of almost any molding material for which an adjustment of the density is desirable, in particular, a molding material containing an elastic aggregate having relatively large diameter particles. While such pavement may be applicable to a playground such as a running track or a playground for handball or socker for which the surface roughness does not present a problem, it cannot be used for a tennis court which requires a fully smooth surface. Of importance is the fact that because a guide piece must be placed on each side of the paving arrangement, a joint is produced between a surface which has already been paved and another surface which is being paved in contiguous relationship with the latter. It is necessary that the joint be subsequently filled out. In addition, the arrangement is bulky, presenting difficulty in its transportation.